The harbinger for consumption of alcohol in undergraduate colleges everywhere. The irony is that the original intention was to conceal the content of the cup, as the drinkers are all underage, versus a clear plastic cup that gives away the amber goodness intrinsic of most beers. There's been such widespread integration of the red plastic drinking cup that it's immediately obvious that a red cup signifies consumption of alcoholic beverages.

You: I'm using my red cup as my vessel for ol' Jack D. ... no one will have any idea that I'm drinking alcohol. I'm deceptive and clever.

1.A device which enables you to signify you are a part of Da Boyzz.
2.A sign you belong to western canada high school. Because lets face it they enjoy being classy and what says classy like a noice red cup.
3.A symbol that you are ready to get FUCKEDDDD UP! and your gonna hook up with some DG's and get some benny's
4. Someething you use to take action in a leasurly game of beerpong or flip cup but only people from western do that lets face it.
5.You are imitating da boyz!!

Grady: Yo bietz are you supplying da red cups for the shindig tonight?

Kyle: Who the fuck do you think i am? joan just bought me a 300 pacck fuck yeh i will!

Grady: K good we are going to isobells house tonight and we wont want to use those gay ass dixie cups she has.Or fucking white cups theys the devil.
OR
Zack: YO BIETZZZMANNN im having a chill time tonight yee know like reaally just chilllll we have weed and brewskies but we need some cups man we hear Da Boyzzz supply them can you hook me up?

a group of individuals (usually in high school, though it can be a lifelong classification) who "party" with plastic red cups (hence the name), but really, no one else cares what they do and they have no social bearing outside their group.

Idiocy. Red cups are to drinkers as rolling papers are to stoners. Both may be used in completely unrelated ways, mainly in consumption, but they have become symbols of a certain scene.

Red cuppin is synonymous with drinking, or with partying in general. It is very popular with young groups of people, namely teens. Underage teens and undergraduate-aged adults alike might attend a red cup party.
It is possible that the red cup trend originated from beer pong, which sometimes uses 12 or 16 oz. plastic cups.

(Red cups MAY be used in bars to indicate that the holder is drinking alcohol, but more involved investigation is required by this author to prove it.)

Not every red cup party will have underage drinkers. Believe it or not, there are a few responsible young adults out there who will not allow underage drinking around their parties, red cup or not.

Red cups are a fad whose popularity and appeal to young adults will contribute to the snowballing demise of the human race.